<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- method:指定当前表单的提交方式 
    默认 GET

action:指定当前表单提交到哪里-->
    <form action="http://localhost:3000" method="POST">
        <input type="text" name="username">
        <input type="password" name="password">
        <input type="submit" name="" id="">
    </form>
</body>

</html>